https://bugs.freedesktop.org/show_bug.cgi?id=52467
--- Comment #10 from Chris bensenq@163.com --- Maybe I have the same problem.
Tested on ubuntu 13.04 and 13.10, my new HD6450 just gives me the same corrupted screen as yours. On windows, it works with no problem.
(In reply to comment #4)
Created attachment 64641 [details] Picture of screen corruption